package com.ymt.bpm.util;


import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.logging.Logger;

public class AES {

	public static final String SEED = "BPM_AES_KEY";

	private static Logger logger = Logger.getLogger(AES.class.getName());

	/**
	 * 加密
	 *
	 * @param content
	 *            需要加密的内容
	 * @param password
	 *            加密密码
	 * @return
	 */
	public static String encrypt(String content, String password) {
		try {
			SecretKey secretKey = getKey(password);
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
			byte[] byteContent = content.getBytes("utf-8");
			cipher.init(Cipher.ENCRYPT_MODE, key);// 初始化
			byte[] result = cipher.doFinal(byteContent);
			return parseByte2HexStr(result); // 加密
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 解密
	 *
	 * @param content
	 *            待解密内容
	 * @param password
	 *            解密密钥
	 * @return
	 */
	public static String decrypt(String content, String password) {
		try {
			SecretKey secretKey = getKey(password);
			byte[] enCodeFormat = secretKey.getEncoded();
			SecretKeySpec key = new SecretKeySpec(enCodeFormat, "AES");
			Cipher cipher = Cipher.getInstance("AES");// 创建密码器
			cipher.init(Cipher.DECRYPT_MODE, key);// 初始化
			byte[] result = cipher.doFinal(parseHexStr2Byte(content));
			return new String(result, "utf-8"); // 加密
		} catch (NoSuchAlgorithmException e) {
			e.printStackTrace();
		} catch (NoSuchPaddingException e) {
			e.printStackTrace();
		} catch (InvalidKeyException e) {
			e.printStackTrace();
		} catch (IllegalBlockSizeException e) {
			//e.printStackTrace();
		} catch (BadPaddingException e) {
			e.printStackTrace();
		} catch (UnsupportedEncodingException e) {
			e.printStackTrace();
		}
		return null;
	}

	/**
	 * 默认seed加密
	 * @param source
	 * @return
	 */
	public static String encrypt(String source) {
		//logger.finer("encrypting:"+source);
		return encrypt(source, SEED);
	}

	/**
	 * 默认seed解密
	 *
	 * @param source 待解密内容
	 * @return
	 */
	public static String decrypt(String source) {
		return decrypt(source, SEED);
	}

	/**
	 * 以默认seed验证
	 * @param decrypted
	 * @param encrypted
	 * @return
	 */
	public static boolean verify(String decrypted, String encrypted) {
		//logger.finer("verifying decrypted="+decrypted + " encrypted="+encrypted);
		if (decrypted==null) {
			return false;
		}
		return decrypted.equals(decrypt(encrypted, SEED));
	}

	/**
	 * 将二进制转换成16进制
	 *
	 * @param buf
	 * @return
	 */
	public static String parseByte2HexStr(byte buf[]) {
		StringBuffer sb = new StringBuffer();
		for (int i = 0; i < buf.length; i++) {
			String hex = Integer.toHexString(buf[i] & 0xFF);
			if (hex.length() == 1) {
				hex = '0' + hex;
			}
			sb.append(hex.toUpperCase());
		}
		return sb.toString();
	}

	/**
	 * 将16进制转换为二进制
	 *
	 * @param hexStr
	 * @return
	 */
	public static byte[] parseHexStr2Byte(String hexStr) {
		if (hexStr.length() < 1) {
			return null;
		}
		byte[] result = new byte[hexStr.length() / 2];
		for (int i = 0; i < hexStr.length() / 2; i++) {
			int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
			int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2),
					16);
			result[i] = (byte) (high * 16 + low);
		}
		return result;
	}

	/**
	 * generate 6 random chars
	 * @return
	 */
	public static String random(int size) {
		String a = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
		char[] rands = new char[size];
		for (int i = 0; i < rands.length; i++)
		{
			int rand = (int) (Math.random() * a.length());
			rands[i] = a.charAt(rand);
		}
		String rtn = "";
		for(int i=0;i<rands.length;i++){
			rtn += rands[i];
		}
		return rtn;
	}

	private static SecretKey getKey(String password) throws NoSuchAlgorithmException {
		SecureRandom secureRandom = SecureRandom.getInstance("SHA1PRNG");
		secureRandom.setSeed(password.getBytes());
		KeyGenerator kgen = KeyGenerator.getInstance("AES");
		kgen.init(secureRandom);
		return kgen.generateKey();
	}

	/**
	 * @param args
	 */

	public static void main(String[] args) {
		String content = "1";
		String password = SEED;
		// 加密
		System.out.println("加密前：" + content);
		String encryptResult = encrypt(content, password);
		System.out.println("加密后：" + encryptResult);
		// 解密
		String decryptResult = decrypt(encryptResult, password);
		System.out.println("解密后：" + decryptResult);
		System.out.println("验证：" + verify(content, encryptResult+"111"));

		String testDecrypt = "D06050E30C3F5D1974ECEACCEF4CDCB22E9A53BFADD611B9A3CA05599497BDD94984F5DFBCE26D2485125C2D2267FE3D";
		System.out.println("解密后：" + decrypt(testDecrypt, password));
	}
}
